1. Field of the Invention
The present invention relates generally to liquid filling systems and, more specifically, to a semi-automated bench top filling system that allows a user to switch between different pump technologies while utilizing a single drive and control unit.
2. Description of the Background
The production container filling industry is faced with a need for filling a wide variety of different types and sizes of containers with different fluids and for running batches as small as only a few units to hundreds or more units. Further, each production run involves specific product requirements that are generally a function of fluid parameters including fill volume (ranging from microliters to liters), viscosity, entrained solids, output volume or other product parameters. These parameters often dictate the use of a particular type of positive displacement pump. The term “positive displacement pump” as used herein refers to any type of pump that forces a fluid to move by displacing a trapped volume of the fluid from a chamber. Examples of positive displacement pumps include, but are not limited to, gear, lobe, piston, and peristaltic pumps.
Conventional filling systems are generally pump-specific in as much as they drive, for example, only a piston pump or only a peristaltic pump. As a result, an entirely separate filling system must be employed when the fluid parameters of different batches call for the use a different type of positive displacement pump. For example, Watson-Marlow Flexicon, a leading manufacturer of peristaltic filling systems and capping equipment for the pharmaceutical, bio-technology, and diagnostic industries, sells a Disposable Filling Machine™. This machine is a table-top pump that provides fast, accurate dispensing of pharmaceutical and biotechnology serums and fluids, permits easy product changeover, eliminates the risk of cross contamination, and simplifies aseptic filling and cleaning validation. However, a single peristaltic pump is used so that the system is not suitable for filling applications commanding a gear, lobe, or piston pump such as for example pumping of fluids having included particulate matter. A separate system utilizing, for example, a lobe pump would be required to be swapped in.
Acquiring and maintaining multiple pumping systems to be swapped in and out entails a significant investment in equipment and overhead and engenders costly “downtime” when changing from one product (or batch) to another. Such costs are obviously to be avoided and attempts have been made in other contexts to develop equipment to do so, notably in the context of medical pumps where it is necessary to swap out dirty pump cartridges for clean ones. Notable examples include U.S. Pat. No. 5,308,320 to Safar et al. (University of Pittsburgh) issued May 3, 1994, which discloses a portable and modular cardiopulmonary bypass apparatus with a pump 76 mounted on a pump console 90 by means of an interchangeable pump base 91 that facilitates attachment of various pump heads.
U.S. Pat. No. 5,316,452 to Bogen et al. (Gilbert Corp) issued May 31, 1994, shows a dispensing assembly utilizing compressible cartridges containing liquid reagents that are interchanged often. Each cartridge pump includes a reagent reservoir that directly empties into a metering chamber. The dispensing assembly may be mounted on a moveable platform, and the interchangeable pump cartridges can be easily exchanged.
U.S. Pat. No. 6,800,069 to Lampropoulos et al. (Merit Medical Systems) issued Oct. 5, 2004, shows a modularized infusion pump that allows a user to modify the configuration with one or more interchangeable manual or automatic pumps to inflate a pressure infuser bag. The modular configuration of the pressure infuser apparatus permits the user to detach and reattach a motorized pump and/or a manual pump to the pressure infuser bag quickly, easily, and efficiently without decreasing the air pressure of the pressure infuser bag.
In a non-medical context, U.S. Pat. No. 4,485,941 to Frates et al. (Nordson Corporation) issued Dec. 4, 1984, shows an apparatus for melting and dispensing thermoplastic material using either a reciprocating piston or a rotary gear pump, the two being interchangeable. Apparently hot melt manufacturers need to suit one line of equipment using rotary gear pumps, and another line of equipment using reciprocating piston pumps. However, no user-guidance is given for the changeover, so this process remains burdensome.
It would thus be desirable to provide a filling system that is capable of docking a gear, lobe, piston, or peristaltic pump and that substantially automates the accurate filling of containers regardless of which pump is mounted by utilizing a user-interface-guided tare weighting procedure to adjust to and dispense the correct amount of fluid by weight.